- #1
katchum
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I've been searching for a DME + H2O boiling point composition curve. Can someone help me here or give me a clue how to calculate the curve?
Searching for DME + H2O Boiling Point Curve: Help Needed
- Thread starter katchum
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- Boiling Boiling point Curve Point
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Discussion Overview
The discussion revolves around the search for a boiling point composition curve for dimethyl ether (DME) and water (H2O). Participants explore methods for calculating or obtaining this curve, including references to experimental data and software tools.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant requests assistance in finding or calculating a DME + H2O boiling point composition curve.
- Another participant suggests that such curves are typically determined experimentally and advises searching the literature.
- A different participant recalls a software program that generates component curves based on input molecules and mentions the use of activity coefficient correlations.
- This participant also references specific models like UNIFAC, UNIQUAC, and NRTL, noting their relevance to certain mixtures.
- Another participant shares that they found a free software tool for calculating vapor-liquid equilibrium (VLE) curves using Antoine coefficients and other component properties.
- Concerns are raised about the reliability of Antoine coefficients, as they are temperature-dependent and may not be valid across the entire pressure/temperature range.
Areas of Agreement / Disagreement
Participants generally agree that experimental data is essential for determining boiling point curves, but there are differing opinions on the reliability of software tools and the use of specific models for calculations.
Contextual Notes
Participants express uncertainty regarding the accuracy of Antoine coefficients and the conditions under which different models should be applied. There is also a lack of consensus on the best approach to obtain the desired boiling point curve.
- #2
Borek
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These things are determined experimentally, so you have to search literature.
- #3
katchum
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I think I saw once that there was a program where you would input molecules and magically you could get a component curve out of it.
It could be that they were using correlations to set up this component curve based on activity coefficients, isn't this true?
It has been 5 years now, so my mind is blurry at this moment.
Edit: I remember things like Uniquac, unifac, nrtl and you had to use one of them specifically when dealing with a certain mixture. But I forgot it all by now... I'll have to dig it up again.
It could be that they were using correlations to set up this component curve based on activity coefficients, isn't this true?
It has been 5 years now, so my mind is blurry at this moment.
Edit: I remember things like Uniquac, unifac, nrtl and you had to use one of them specifically when dealing with a certain mixture. But I forgot it all by now... I'll have to dig it up again.
Last edited:
- #4
katchum
- 116
- 0
Just to update the status: I've found a free software VLE calculator tool where you can input Antoine coefficients, molecular weight and density of the components. You can then calculate the composition curves with UNIFAC. It's a pretty awesome thing to use!
- #5
Borek
Mentor
- 29,203
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katchum said:
Coefficients are found experimentally and Antoine equation usually doesn't work for the entire pressure/temperature range. In other words - coefficients itself are temperature dependent. So you better treat results of these calculations with care. But they are better than nothing
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